The determination of the shear modulus profile within the seabed is an important and challenging problem in geophysics, underwater acoustics, hydrodynamics and geotechnical engineering. Such information is needed for modeling the propagation of seismic waves, acoustic waves and gravity water waves in the ocean. Such information is also important for the design of foundations for offshore structures.
Existing direct methods using penetrometers and boreholes are costly and time consuming thereby being impractical for surveying a large area of seafloor. On the other hand, the bottom shear properties are very difficult to extract by indirect methods using acoustic waves because the shear waves are difficult to excite acoustically. Active seismic methods using interface waves are limited in that the necessary forward and inverse analyses are quite involved numerically.